With the development of technology, portable electronic devices, such as mobile phones, tablets or notebooks, are widely used in daily life. Portable charger, is a device to extend the portable electronic device's uptime. Generally, a portable charger consists of a rechargeable battery and a voltage adapter, and the rechargeable can provide electricity to the portable electronic device by connecting it to the portable electronic device through a wire.
However, the output voltage of conventional portable chargers is only exclusive to some portable electronic devices, so the applicability of the conventional portable chargers is restricted.